Porous membranes for high pressure filtration

Abstract

The present invention relates to a porous membrane suitable for use in high pressure filtration method.

1 - 15 . (canceled) 
     
     
         16 . A method for purifying a fluid containing at least one contaminant, said method comprising the steps of
 (I) providing a fluid containing at least one contaminant;   (II) providing a membrane [membrane (PSP)] comprising at least one porous layer [layer (PSP)] comprising at least one aromatic sulfone polymer [polymer (SP)] and at least one polyphenylene polymer [polymer (PP)];   (III) contacting said fluid containing at least one contaminant and said membrane (PSP) by applying a pressure higher than 1 bar to said fluid; and   (IV) recovering the fluid free from said at least one contaminant.   
     
     
         17 . The method according to claim  1 , wherein said membrane (PSP) comprises said layer (PSP) as the only layer or said membrane (PSP) is a multi-layered membrane. 
     
     
         18 . The method according to claim  1 , wherein said polymer (SP) is a polymer comprising at least one group of formula —Ar—SO 2 —Ar′— [recurring units (R SP )], wherein Ar and Ar′, equal to or different from each other, are aromatic groups, and wherein more than 50% by moles of the recurring units of said polymer (SP) are connected by ether linkages in the main chain. 
     
     
         19 . The method according to  claim 18 , wherein the recurring units (R SP ) are selected from the group consisting of:
 (I) recurring units (R SP-1 ) of formula:
   —Ar 1 -(T′—Ar 2 ) n —O—Ar 3 —SO 2 —[Ar 4 -(T-Ar 2 ) n —SO 2 ] m —Ar 5 —O—  (R SP-1 )
 
   wherein:
 Ar 1 , Ar 2 , Ar 3 , Ar 4 , and Ar 5 , equal to or different from each other and at each occurrence, are independently aromatic mono- or polynuclear groups; 
 T and T′, equal to or different from each other and at each occurrence, is independently a bond or a divalent group optionally comprising one or more than one heteroatoms; preferably T′ is selected from the group consisting of a bond, —CH 2 —, —C(O)—, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(═CCl 2 )—, —SO 2 —, —C(CH 3 )(CH 2 CH 2 COOH)—, and a group of formula: 
   
       
         
           
           
               
               
           
         
       
       and
 preferably T is selected from the group consisting of a bond, —CH 2 —, —C(O)—, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(═CCl 2 )—, —C(CH 3 )(CH 2 CH 2 COOH)—, and a group of formula: 
 
       
         
           
           
               
               
           
         
       
       and
 and m, equal to or different from each other, are independently zero or an integer of 1 to 5; 
 (II) recurring units (R SP-2 ) of formula:
   —Ar *1 —SO 2 —[Ar *2 -(T*-Ar *3 ) n* —SO 2 ] m* —Ar *4 -E-  (R SP-2 )
 
 
 wherein
 each of Ar *1 , Ar *2 , Ar *3  and Ar *4 , equal to or different from each other at each occurrence, is an aromatic moiety; 
 n* and m*, equal to or different from each other, are independently zero or an integer of 1 to 5; 
 T* is a bond or a divalent group optionally comprising one or more than one heteroatom; preferably T* is selected from the group consisting of a bond, —CH 2 —, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(═CCl 2 )—, —C(CH 3 )(CH 2 CH 2 COOH)—, and a group of formula: 
 
 
       
         
           
           
               
               
           
         
         and
 E is a 1,4:3,6-dianhydrohexitol sugar diol unit selected from one or more of formulae (E-1) to (E-3): 
 
       
       
         
           
           
               
               
           
         
       
     
     
         20 . The method according to  claim 18 , wherein said polymer (SP) is selected from poly(phenylene sulfone) polymers [polymers (PPSU)], poly(sulfone) polymers [polymers (PSU)] and poly(ether sulfone) polymers [polymers (PESU)]. 
     
     
         21 . The method according to  claim 20 , wherein
 said poly(phenylene sulfone) polymer [polymer (PPSU)] is a polymer comprising recurring units wherein more than 50% by moles of the recurring units (R SP-1 ) of said polymer (PPSU) are recurring units (R PPSU ) of formula (K-A):   
       
         
           
           
               
               
           
         
         said poly(sulfone) polymer [polymer (PSU)] is an aromatic sulfone polymer wherein at least 50% by moles of the recurring units (R SP-1 ) of said polymer (PSU) are recurring units (R PSU ) of formula: 
       
       
         
           
           
               
               
           
         
         said poly(ether sulfone) polymer [polymer (PESU)] is a polymer wherein more than 50% by moles of the recurring units (R SP-1 ) of said polymer (PESU) are recurring units (R PESU ) of formula: 
       
       
         
           
           
               
               
           
         
         wherein each of R′, equal to or different from each other, is selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium, and each of j′, equal to or different from each other and at each occurrence, is independently zero or is an integer from 0 to 4. 
       
     
     
         22 . The method according to  claim 16 , wherein said polymer (PP) comprises at least about 10 mole percent (per 100 moles of polymer (PP)) of repeat units (R pm ) represented by the following formula: 
       
         
           
           
               
               
           
         
         and at least about 10 mol percent repeat units (R pp ) represented by the following formula 
       
       
         
           
           
               
               
           
         
         wherein 
         R 1 , R 2 , R 3 , R 4  R 5 , R 6 , R 7 , and R 8  are each independently selected from the group consisting of hydrogen, alkyl, aryl, alkoxy, aryloxy, alkylketone, arylketone, fluoroalkyl, fluoroaryl, bromoalkyl, bromoaryl, chloroalkyl, chloroaryl, alkylsulfone, arylsulfone, alkylamide, arylamide, alkylester, arylester, fluorine, chlorine, and bromine. 
       
     
     
         23 . The method according to  claim 22 , wherein
 one or more of R 1 , R 2 , R 3 , and R 4  is independently represented by formula Ar-T-, wherein   Ar is represented by a formula selected from the following group of,   
       
         
           
           
               
               
           
         
         wherein 
         each R j , R k  and R l  is independently selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium, 
         with j and l, equal or different from each other, being independently 0, 1, 2, 3, 4, or 5 and, 
         k, equal or different from j or l, being independently 0, 1, 2, 3 or 4; 
         T is selected from the group consisting of —CH 2 —; —O—; —SO 2 —; —S—; —C(O)—; —C(CH 3 ) 2 —; —C(CF 3 ) 2 —; —C(═CCl 2 )—; —C(CH 3 )(CH 2 CH 2 COOH)—; —N═N—; —R a C═CR b —, 
         wherein 
         each R a  and R b , independently of one another, is hydrogen, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, or C 6 -C 18 -aryl group; —(CH 2 ) n — and —(CF 2 ) n — with n being an integer from 1 to 6; 
         a linear or branched aliphatic divalent group having from 1 to 6 carbon atoms; and/or 
         wherein one or more of R 5 , R 6 , R 7 , and R 8  is independently represented by formula Ar″-T″-, 
         wherein 
         Ar″ is represented by a formula selected from the following group of formulae 
       
       
         
           
           
               
               
           
         
         wherein 
         each R j″ , R k″ , and R l″  is independently selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium, 
         j″ and l″, equal or different from each other being independently 0, 1, 2, 3, 4, or 5 and, 
         k″, equal or different from j″ or l″, being independently 0, 1, 2, 3 or 4; 
         T″ is selected from the group consisting of —CH 2 —; —O—; —SO 2 —; —S—; —C(O)—; —C(CH 3 ) 2 —; —C(CF 3 ) 2 —; —C(═CCl 2 )—; —C(CH 3 )(CH 2 CH 2 COOH)—; —N═N—; —R a C═CR b —, 
         wherein each R a  and R b , independently of one another, is hydrogen, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, or C 6 -C 18 -aryl group; —(CH 2 ) n — and —(CF 2 ) n — with n being an integer from 1 to 6; a linear or branched aliphatic divalent group having from 1 to 6 carbon atoms. 
       
     
     
         24 . The method according to  claim 22 , wherein the repeat unit (R pm ) is represented by the formula 
       
         
           
           
               
               
           
         
         and polymer (PP) comprises at least about 30 mole percent of repeat units (R pm ). 
       
     
     
         25 . The method according to  claim 22 , wherein the repeat unit (R pp ) is represented by the formula 
       
         
           
           
               
               
           
         
         and polymer (PP) comprises at least about 40 mole percent repeat units (R pp ). 
       
     
     
         26 . The method according to claim  1 , wherein said method is for purifying non-drinkable water, said fluid is saline water or brackish water, said contaminant is the salts content dissolved into said fluid, and said membrane (PSP) is a multi-layered membrane comprising (I) a substrate layer, (II) an outer layer consisting of aromatic polyamides and (III) the layer (PSP), said layer (PSP) being interposed between said substrate layer and said outer layer. 
     
     
         27 . The method according to claim  1 , wherein said fluid containing at least one contaminant is a liquid phase or a gas phase. 
     
     
         28 . The method according to claim  1 , wherein said layer (PSP) is obtained from a [composition (C)] comprising at least one polymer (SP), at least one polymer (PP) and at least one solvent [medium (L)]. 
     
     
         29 . The method according to  claim 28 , wherein said composition (C) is a liquid composition [composition (C L )] comprising at least one medium (L), at least one polymer (PP) in an amount of from 0.1 to 30 wt. % based on the total weight of said composition (C L ) and at least one polymer (SP) in an amount of from 7 to 60 wt. % based on the total weight of said composition (C L ), the remaining amount up to 100 wt. % of said composition (C L ) being provided by medium (L). 
     
     
         30 . A membrane [membrane (PSP*)] comprising at least one porous layer [layer (PSP*)] obtained from a composition [composition (C*)] comprising at least one sulfone polymer [polymer (SP)] in an amount of from 7 to 60 wt. % based on the total weight of said composition (C*), at least one polyphenylene polymer [polymer (PP)] in an amount of from 0.1 to less than 30 wt. % based on the total weight of said composition (C*), and at least one solvent [medium (L)] in an amount of from 10 to 92.9 wt. % based on the weight of said composition (C*).